A Midland university piloting a new test to select students said it had concerns about putting pupils through another tier of exams.
Warwick University is one of seven higher education institutions currently trying out the new method of assessing candidates.
The uniTest aims to give admissions bosses a testing tool in the face of an increased number of A-grade A-level students making it harder for them to pick the best.
It will also aim to prevent universities setting their own entrance exams.
The test is designed to identify reasoning and thinking skills and early results suggest some A-level students might be under-selling themselves when choosing a university.
But Warwick University spokesman Peter Dunn said: "There are a lot of things we would want to be assured of.
"They tell us it is a mathematical reasoning test that you can't prepare for. We would want to be assured of that so schools don't have to put pupils through another level of tests.
"Also there is a cost issue. We would want to make sure costs were kept to a minimum."
The Warwick trial will help assess whether the test is a reasonable tool for predicting degree results that students go on to achieve.
It is hoped a single test running along side A-levels will work better for both students and universities.
Its introduction is being examined as Ministers look to increasing the proportion of 18 to 30-year-olds entering higher education from 42 per cent currently to half.